1. Field of the Invention
The present invention relates to a controller for an axial-gap motor.
2. Description of the Related Art
Hitherto, there has been known an axial-gap motor equipped with a rotor having permanent magnets, two stators provided, one each of which is disposed on each side of the rotor in the rotational axial direction of the rotor, and armature windings wrapped around each of the stators, as disclosed in, for example, Japanese Patent Application Laid-Open No. H10-271784 (hereinafter referred to as cited document 1) and Japanese Patent Application Laid-Open No. 2001-136721 (hereinafter referred to as cited document 2). Such an axial-gap motor is capable of generating a relatively high output torque while achieving a reduced length of the rotor of the motor in the axial direction.
According to the techniques disclosed in the above cited documents 1 and 2, the energization of an axial-gap motor is controlled by the passage of current through the armature windings of the two stators, one each of which is disposed on each side of the rotor. This arrangement reduces the leakage of magnetic fluxes in the armatures of the stators, thus leading to increased output torque of the motor.
Here, it is conceivable to operate the axial-gap motor also as a generator, so that the motor runs in a power running mode and a regenerating mode. However, the cited documents 1 and 2 do not refer to any construction for operating the axial-gap motor in an energization mode for running the motor in a regenerative mode or the like other than the one for operating the motor in a power running mode.